The goal of this project is to provide a broadly available research tool that allows the direct measurement of protein expression heterogeneity through massively parallel, single-cell resolution Western blot analyses. This method promises to revolutionize diverse fields such as stem cell differentiation, drug discovery, and cancer biology by allowing researchers to directly study heterogeneity in protein expression and cellular signaling and function. This capability will enable many clinical advances including improved cancer therapeutic efficacy, companion diagnostic development for targeted therapies, and cell-based therapies for regenerative medicine. In response to a specific NIH funding opportunity announcement that calls for proposals to help move useful technologies from non-commercial laboratories into the commercial marketplace, Zephyrus Biosciences is commercializing a single-cell Western blotting technology that has been developed by researchers at the University of California, Berkeley with research support from the NIH. To allow initial deployment of this technology outside of the inventing lab, the proposed project has the following two specific aims: (1) develop a packaging and storage approach that protects the disposable chips during shipping and prevents degradation during storage, and (2) design and prototype instrumentation that executes the required electrophoretic separation and protein binding steps while being easy to use for researchers that were not involved in the development of the technology. Once these aims have been accomplished, the prototype chips and instrumentation will be ready for pilot deployment to early-adopters who need only have access to an electrophoresis high voltage supply and a standard microarray scanner. A Phase II proposal will focus on scaling disposable production and integration of optical detection into the instrument.